Department of Agriculture inspectors have been placed on alert to prevent the illegal importation of calves from Britain.
Attempts to smuggle animals into the Republic through the North have been feared since the collapse of the market for young calves in Britain.
Farmers in Britain are unable to sell top-quality calves and have a surplus of at least 600,000. Farmers in Wales have been dumping calves in phone boxes and on roads.
The crisis has been caused by the ending of the so-called "Herod Scheme", introduced by the EU to reduce beef production in Europe by slaughtering calves under 10 days old for a £70 grant. Funds to support this scheme in Britain have now dried up. Farmers are finding that their calves have no market value abroad since the BSE crisis.
While the special road checks put in place by the Government to prevent any movement of animals from the North immediately after the BSE crisis in March 1996 have been scaled down, mobile patrols are to be increased.
Calf prices here, unlike Britain, have remained quite high, strengthened by a demand on the Continent, especially in Spain and the Netherlands.
The "Herod Scheme" is still in operation in the Republic but is now being used by farmers only to dispose of weak or ill animals.
A Department of Agriculture and Food spokesman said yesterday its staff had been asked to increase vigilance on the calf trade and would continue to monitor unusual patterns.
"We are lucky here because we now have full registration of all calves who must have their own passports and tags. It would be difficult to circumvent the controls we have in place," he said.